Simple one-pot synthesis of ZnO/Ag heterostructures and the application in visible-light-responsive photocatalysis

Abstract

The development of efficient visible-light-driven photocatalysts remains one of the greatest scientific challenges of this century. In this paper, visible light active ZnO/Ag heterostructures have been synthesized on a large-scale by a simple one-pot synthesis method. The influence of the Zn/Ag ratio on the properties of heterostructures was investigated in detail. In light of the formation process of heterostructures, ZnO rods and Ag nanoparticles can link each other by strong bonds due to the bridging effect of NH₃, which is found to be essential for the efficient visible-light-responsive activity and stability. These heterostructures were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray fluorescence, Raman and UV-vis spectroscopy. These results indicate that ZnO/Ag composition is well-constructed with a band gap of 2.85 eV. Moreover, photocatalytic experiments show that these ZnO/Ag heterostructures are robust and exhibit high photocatalytic activity for the efficient separation of electron–hole pairs and the subsequent generation of hydroxyl radicals.